Piranga ludoviciana

Geographic Range

The geographic region of western tanagers ( Piranga ludoviciana ) follows the forest, ranging from the western coasts of North America and Central America from Alaska all the way to Panama. This region stretches as far east as the Northwest Territories in Canada and the western edge of North Dakota, Nebraska, and Texas. Their main residency and breeding territory is in the far northern region of Canada and they migrate south during the winter. However, they have been known to breed in their wintering regions of South America.

• Biogeographic Regions
• nearctic nearctic
  • native native
• ethiopian ethiopian
  • introduced introduced
• neotropical neotropical
  • native native

Habitat

Western tanagers arrive in their breeding grounds in the spring and breed in open coniferous forests and mixed woodlands. They leave the northern locations in late summer and spend the winters in the open mountain pine woodlands, parks, gardens, desert oases, riparian areas, and orchards. In their wintering range, they occupy pine and pine-oak woodlands as well as low-canopied scrub forests. They have been seen in elevations as high as 10,000 feet and as low as 330 feet.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• taiga taiga
• forest forest
• scrub forest scrub forest
• mountains mountains

• Other Habitat Features
• riparian riparian

Physical Description

Western tanagers average around 18 cm in length, with an average weight of 28 grams. They have a wingspan of approximately 28 to 30 cm, with rounded wings and a fan-shaped tail. Their bill is an all-purpose beak, meaning they can catch food, build a nest, preen, dig holes, and care for their young. Their eyes are sepia brown in adolescent birds, grayish brown or black in adult males, and reddish brown to burnt umber in adult females. Among males, their breast is primarily yellow, their back and wings are primarily black, and their entire head is red. Their wings have two bright yellow wing bars. Females are pale in comparison, with an olive green upper back and head. Their wings are grey with two wing bars and their tails are greyish brown or olive green. After hatching, young have white or pale gray down on their head, back, and wings, and their wing bars become visible after 10 days.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently
• male more colorful

Reproduction

Western tanagers are monogamous. Pairs form during migration or on the wintering grounds, mostly in South America. Pairs that form on the wintering grounds may migrate together to the breeding grounds. Males establish and defend their territory by singing and chasing away intruders. However, males are not known to perform any displays to attract mates.

• Mating System
• monogamous monogamous

The earliest birds may arrive on the breeding grounds in April, while most birds arrive by early May. On average, females and first-year males arrive at breeding grounds later. Both sexes are sexually mature after two years. Although western tanagers are socially monogamous, males are known to move outside the territory they defend to mate with other females. Females build small cup-like nests from grass and twigs in about 4 to 5 days. Males feed the females during the nest building and the egg laying process. On average, the eggs are 23 mm long, about 3.35 grams, and are pale blue or bluish green. The eggs are blotched with brownish speckles that form a thick wreath around the larger end of the egg. Females lay around 3 to 5 eggs, which takes about a day per egg. The eggs are incubated by the female for approximately 13 days. The young are fed by both parents and fledge within 15 days. The young do not become independent until about two weeks after fledging. Western tanagers may leave their breeding grounds as early as July, but typically do not begin migration until August.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Female western tanagers incubate the eggs alone, but both males and females feed the young. Both parents continue feeding the fledglings for about two more weeks after they have left the nest. The young are known to stay on the breeding grounds even after the adults have left.

• Parental Investment
• altricial altricial
• male parental care male parental care
• female parental care female parental care
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

Western tanagers have been known to live up to 15.3 years, but their average life span is around 8 years. In addition to predation, mortality can also be caused by food deprivation resulting from severe weather.

Behavior

Western tanager migrate long distances and migrate alone, in pairs, or in groups of about 30. Migration occurs at night, at very high altitudes. They form loose associations with other bird species such as Townsend's warblers , purple finches , and mountain chickadees . Males chase other males that intrude in their territory and females chase other females. Western tanagers also charge at smaller birds and physical contact is sometimes made due to the reaction of the startled victim. Western tanagers can be difficult to spot because they forage in the upper branches of trees and move slowly and deliberately, but in flight they are swift and direct.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• crepuscular crepuscular
• motile motile
• migratory migratory

Home Range

There are a few studies of home territories for western tanagers. A conifer forest in Idaho averaged a home range size of 39,100 square meters, while in Montana; they have an average home range of 28,300 square meters.

Communication and Perception

Western tanagers generally communicate through song. Their song is similar to American robins' , but pauses after each phrase and sounds more hoarse. Their calls are short and explosive and used by both sexes and their young. The young sound more musical, while the female is less eloquent. Her song is more repetitive, with an average of 2 to 5 phrases. Males have more articulated and more frequent vocalizations, with 4 to 7 song phrases. Males sing primarily on the breeding grounds. Males are attracted to the playback of female songs and males will also counter-sing when they hear neighboring males. Song rates are most frequent in the morning and slowly decrease during the day. When a female perceives a threat, she gives a series of nervous calls. When the male hears the nervous call of his mate, he gives a loud series of nervous calls and flies from branch to branch.

• Communication Channels
• acoustic acoustic

• Other Communication Modes
• choruses choruses

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Western tanagers are insectivores and catch insects while they are in flight. Vespid wasps are not eaten by other migratory birds, but are often preferred by western tanagers. They also eat fruits and nectar from plants. During the winter they eat both insects and fruit.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• insects

• Plant Foods
• fruit
• nectar
• sap or other plant fluids

Predation

There are several birds that prey on western tanagers. Common predators are hawks , owls , and jays . Nest predators include owls , jays , black bears , prairie rattlesnakes , bull snakes , common ravens , American crows , squirrels , and even domestic cats . Their anti-predator adaptations include tail cocking, wing flapping, and loud nervous calls. Western tanagers swoop towards intruders when they are too close to their nest.

Ecosystem Roles

Western tanagers are prey for many birds and mammals. Brown-headed cowbirds are known to parasitize western tanager nests and also reduce the number of western tanagers that are able to fledge per nest. Western tanagers are known to mob cowbirds, but cowbirds are still able to remove some of the western tanagers' eggs and lay their own. After hatching, western tanagers will raise the cowbirds to fledging. Blowfly larvae are also known to subcutaneously invade fledglings, which results in death.

Economic Importance for Humans: Positive

Western tanagers are known to eat several insects and are viewed as a form of pest control for humans.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

There are no known negative effects of western tanagers on humans.

Conservation Status

Western tanagers are not threatened, in fact, the species has a large range. Western tanagers are protected under the U.S. Migratory Bird Act.

Other Comments

Western tanagers have a red pigment on their faces caused by rhodoxanthin, a pigment that is very rare in birds. This pigmentation comes from the insects western tanagers eat, and the insects acquire it from plants. Their yellow color originates from the melanin pigmented by carotenoids.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Jeneil Boles (author), University of Wyoming, Hayley Lanier (editor), University of Wyoming - Casper, Leila Siciliano Martina (editor), Texas State University.

References

Birdlife International, 2012. " Piranga ludoviciana " (On-line). The IUCN Red List of Threatened Species. Accessed November 06, 2013 at http://www.iucnredlist.org/details/22722471/0 .

Carlise, J., K. Olmstead, C. Richart, D. Swanson. 2012. Food availability, foraging behavior, and diet of autumn migrant landbirds in the Boise Foothills of Southwestern Idaho. The Condor , 114.3: 449-461.

Davis, C. 2001. "California Partners in Flight Coniferous Bird Conservation Plan for the Western Tanager ( Piranga ludoviciana )" (On-line). Accessed November 01, 2013 at http://www.prbo.org/calpif/htmldocs/species/conifer/wetacct.html .

Hudon, J. 1999. The Birds of North America . Philadelphia, PA: The Academy of Natural Sciences.

Hudon, J. 1991. Unusual carotenoid use by the western tanager ( Piranaga ludoviciana ) and its evolutionary implications. Canadian Journal of Zoology , 69: 2311-2320.

Lee, V. 2012. "Western Tanager Tags: Birds, Through the Looking Glass of Val Lee" (On-line). Accessed November 02, 2013 at http://birdsbyval.wordpress.com/2012/04/07/through-the-looking-glass-of-val-lee-western-tanager/ .

Magalhaes, J. 2012. "AnAge entry for Piranga ludoviciana " (On-line). The Animal Aging and Longevity Database. Accessed November 13, 2013 at http://genomics.senescence.info/species/entry.php?species=Piranga_ludoviciana .

Meyer, R. 2006. "Fire Effects Information System" (On-line). Accessed November 04, 2013 at http://www.fs.fed.us/database/feis/ .

Monroy-Ojeda, A., M. Grosselet, G. Ruiz, E. Del Valle. 2013. Winter site fidelity and winter residency of six migratory neotropical species in Mexico. The Wilson Journal of Ornithology , 125.1: 192 -196.

Samuel, M., D. Pierce, E. Garton. 1985. Identifying areas of concentrated use within the home range. Journal of Animal Ecology , 54: 711-719.

Stalling, D. 2012. "Montana Outdoors Portrait: Western Tanager Piranga ludoviciana " (On-line). Accessed November 04, 2013 at http://fwp.mt.gov/mtoutdoors/HTML/articles/portraits/2012/westerntanager.htm#.UniHkfmsj5w .

The Cornell Lab of Ornithology. 2013. "Western Tanager" (On-line). All About Birds. Accessed November 24, 2013 at http://www.allaboutbirds.org/guide/western_tanager/id .